1. Field of the Invention
The present invention relates to wireless Universal Serial Bus (USB), and more particularly, to a method for broadcasting a data packet and receiving the data packet in a wireless USB environment, a wireless USB host, and a wireless USB device.
2. Description of the Related Art
With the development of communication and network technologies, the network environment has recently been evolving from a wired network environment using a cable medium such as a coaxial cable or an optical cable into a wireless network environment using radio signals in various frequency bands.
Wireless networks are classified into two types—an infrastructure mode network and an ad-hoc mode network as shown in FIGS. 1 and 2.
Furthermore, ad-hoc mode wireless networks can be classified into two types based on the presence of a coordinator. In one type of network, a randomly selected wireless device acts as a coordinator that assigns channel time to other wireless devices within the same wireless network for data transmission and the other wireless devices are allowed to transmit data only at the assigned time.
The other type of network allows all network devices to coordinate channel access for transmission of data packet at any time desired without using a coordinator.
A wireless interface for connecting network devices in a wireless manner is needed to perform communication in a wireless network environment. Infrared Data Association (IrDA) and Bluetooth can be used as a wireless interface. Research into wireless USB for making conventional wired USB wireless is now being conducted.
USB provides data transfer rates of up to 12 Mbps while other serial ports support speeds of up to 100 Kbps. The use of USB as an interface between network devices eliminates the need to install complicated adapters. The use of USB also eliminates the need to separately set up software or hardware when peripheral devices are connected to a personal computer (PC). USB connects all kinds of peripheral devices to a PC through the same connector, thus significantly reducing the number of ports. USB also is easy to install and allows miniaturization of a portable PC.
USB is designed to basically support one-to-one communication between a host and a device. However, for wireless USB using a wireless medium in which a data transmission path is not fixed, a technique that allows a host to broadcast a data packet to a number of devices in a wireless USB environment as well as one-to-one communication between the host and a device is required. Recently, USB has been widely used for connection between independent devices such as camcorders and digital cameras and a PC as well as connection between peripheral devices and a PC. Thus, there is an increasing need for a technique for broadcasting a data packet in a wireless USB environment.
Korean Laid-open Publication No. 10-1999-23310, entitled “Wireless Device and Method for Establishing Connection between Wireless Devices”, proposes a technique for implementing wireless USB. However, the proposed method necessitates the installation of a separate wireless hub and ports unlike wireless USB technology. Furthermore, because the method disclosed in the above-cited reference uses conventional USB technology and intends to implement wireless USB by converting a USB signal into a wireless signal, it is difficult to broadcast a data packet using the method.